Random acts of kindness are liable to get you killed in times of tyranny and mass hysteria, a fact that makes Paul Rusesabagina all the more remarkable. When the African nation of Rwanda erupted in genocidal warfare in 1994, Rusesabagina (Don Cheadle) saved scores of Tutsi refugees from slaughter by sheltering them in the Belgium- owned luxury hotel where he worked. For this kindness, he nearly paid with his life. Many times.

Terry George's “Hotel Rwanda” tells Rusesabagina's story, and it is, without a doubt, one of the most penetrating, eye-opening tales of heroism and unbowed humanity you'll ever see. The power of George's film resides not in the direction — which tends to be stagey and unnecessarily sanitized (who ever heard of a PG-13 genocide?) — but in a lucid, moving script and a terrific group of actors, led by Cheadle (“Ocean's Twelve”). Pegged for greatness since stomping his way into America's critical consciousness in “Devil in a Blue Dress” (1995), Cheadle finally delivers the knock-out performance for which audiences have long waited. “Hotel Rwanda” would be lost without him.

George — a superlative screenwriter (“In the Name of the Father”) with limited behind-the-camera experience (“Some Mother's Son”) — presents Rusesabagina as Africa's answer to Oskar Schindler; an ambitious sweet- talker whose sense of compassion and social responsibility ultimately overwhelm his practical, selfish side. Shaking hands and greasing palms, slipping the occasional bottle of single- malt scotch to a highly placed acquaintance in the army (Fana Mokoena), Rusesabagina is perfectly suited to manage the posh Hotel Mille Collines: he's always working the angles, always composed.

Conversely, the key to Cheadle's performance are the cracks in his composure. When the wrath of the Hutu militia spills into the streets and neighborhoods, Rusesabagina (who is Hutu himself and thus, not a direct target) swiftly applies his deal-making skills to the survival of the hundreds of Tutsis in his care. If projecting a sense of unease is art, then projecting a sense of unease concealed by a facade of calm professionalism is art multiplied, and Cheadle makes it happen.

Gruff-but-lovable Nick Nolte (“Prince of Tides”) is an earthquake of impotent indignation as a United Nations peacekeeper frustrated by the world's indifferent response to the Rwanda crisis, but it's “Dirty Pretty Things” actress Sophie Okonedo, as Rusesabagina's Tutsi wife Tatiana, who leaves the deepest impression among Cheadle's supporting cast (Joaquin Phoenix is excellent in a brief role as a war photographer). The movie's sweetest, simplest scenes involve Rusesabagina's efforts to romantically comfort his wife — a bottle of wine, a candlelight dinner on the rooftop — as their world collapses around them. George promulgates the idea that spousal devotion can flourish in even the most trying circumstances, and Cheadle and Okonedo are so good together, we believe it.